The stator vanes and the rotor blades in a gas turbine are exposed to the high temperature of the working fluid passing the vanes and the blades. Due to the high temperature a significant oxidation of the base alloy can occur at the leading edge of an airfoil of the stator vane or, the rotor blade. Furthermore, oxidation at the inner platform of the inner shroud and/or outer shroud of the stator vane or the rotor blade can also occur. Such degradation is currently the life limiting mechanism on this component.
EP 0 980 960 A2 discloses a bowed nozzle vane with a selective thermal barrier coating. A turbine nozzle comprises an outer band and an inner band between which a plurality of vanes extends. The vanes comprise respective leading edges and trailing edges. Furthermore, one side of the respective vanes is a pressure side and the opposed side is a suction side extending between the leading edge and the trailing edge.
EP 2 362 068 A1 discloses a turbine airfoil which comprises an airfoil body with a leading edge, a trailing edge, an exterior surface including a suction side extending from the leading edge to the trailing edge and a pressure side extending from the leading edge to the trailing edge. Furthermore, a thermal barrier coating system is presented in a coated surface section and an uncoated surface region where a thermal barrier coating system is not present is disclosed. The thermal barrier coating system is located at a suction side of the turbine airfoil.
U.S. Pat. No. 6,126,400 A1 discloses a thermal barrier coating wrap for a turbine airfoil. An airfoil body comprises a leading edge and a trailing edge. Furthermore, the airfoil body comprises a convex side extending between the leading edge and the trailing edge. The airfoil body extends between a radially outer band and a radially inner band comprising a base. A thermal barrier coating is applied e.g. to both sides of the airfoil body.
DE 10 2006 048 685 discloses a turbine vane with a thermal barrier coating. A layer thickness of the thermal barrier coating on the suction side decreases continuously initially up to a narrow point of a flow channel inside the turbine vane and then increases continuously again.
U.S. Pat. No. 6,106,231 A discloses a partially coated airfoil comprising a leading edge and a trailing edge. The surfaces of concave side, convex side, leading edge and trailing edge define an outer surface of the airfoil.
US 2009/0074961 A1 comprises a ceramic coating for imparting one or more of a variety of functional characteristics to one or more components or portions of an engine, such as blades, vanes and shrouds of a turbine engine. The surfaces of the components may be partially coated with a ceramic coating.